diff --git a/Casks/game-porting-toolkit.rb b/Casks/game-porting-toolkit.rb
index 063be26..7706328 100644
--- a/Casks/game-porting-toolkit.rb
+++ b/Casks/game-porting-toolkit.rb
@@ -30,7 +30,8 @@
   binary "#{appdir}/Game Porting Toolkit.app/Contents/Resources/wine/bin/wineserver"
 
   postflight do
-    system "xattr", "-drs", "com.apple.quarantine", "#{appdir}/Game Porting Toolkit.app"
+    system "/usr/bin/xattr", "-drs", "com.apple.quarantine", "#{appdir}/Game Porting Toolkit.app"
+    system "/usr/bin/codesign", "--force", "--deep", "-s", "-", "#{appdir}/Game Porting Toolkit.app"
   end
 
   zap trash: [
diff --git a/Casks/wine-crossover.rb b/Casks/wine-crossover.rb
index eb947f2..ae25e68 100644
--- a/Casks/wine-crossover.rb
+++ b/Casks/wine-crossover.rb
@@ -40,7 +40,8 @@
   binary "#{appdir}/Wine Crossover.app/Contents/Resources/wine/bin/wineserver"
 
   postflight do
-    system "xattr", "-drs", "com.apple.quarantine", "#{appdir}/Wine Crossover.app"
+    system "/usr/bin/xattr", "-drs", "com.apple.quarantine", "#{appdir}/Wine Crossover.app"
+    system "/usr/bin/codesign", "--force", "--deep", "-s", "-", "#{appdir}/Wine Crossover.app"
   end
 
   caveats <<~EOS
diff --git a/Casks/wineskin-devel.rb b/Casks/wineskin-devel.rb
index ee2d137..8877fad 100644
--- a/Casks/wineskin-devel.rb
+++ b/Casks/wineskin-devel.rb
@@ -16,8 +16,9 @@
 
   # Workaround issue until it's fixed in Winery
   # https://github.com/Gcenx/WineskinServer/issues/96
-  preflight do
-    system "xattr", "-drs", "com.apple.quarantine", "#{appdir}/Wineskin Winery.app"
+  postflight do
+    system "/usr/bin/xattr", "-drs", "com.apple.quarantine", "#{appdir}/Wineskin Winery.app"
+    system "/usr/bin/codesign", "--force", "--deep", "-s", "-", "#{appdir}/Wineskin Winery.app"
     system_command "/bin/mkdir", args: ["-p", "/Users/#{ENV.fetch("USER")}/Applications/Wineskin"], sudo: false
   end
 
diff --git a/Casks/wineskin.rb b/Casks/wineskin.rb
index f4bb052..8b75547 100644
--- a/Casks/wineskin.rb
+++ b/Casks/wineskin.rb
@@ -17,8 +17,9 @@
 
   # Workaround issue until it's fixed in Winery
   # https://github.com/Gcenx/WineskinServer/issues/96
-  preflight do
-    system "xattr", "-drs", "com.apple.quarantine", "#{appdir}/Wineskin Winery.app"
+  postflight do
+    system "/usr/bin/xattr", "-drs", "com.apple.quarantine", "#{appdir}/Wineskin Winery.app"
+    system "/usr/bin/codesign", "--force", "--deep", "-s", "-", "#{appdir}/Wineskin Winery.app"
     system_command "/bin/mkdir", args: ["-p", "/Users/#{ENV.fetch("USER")}/Applications/Wineskin"], sudo: false
   end